Shell fuse



May 29, 1923. 1,456,641 v o. D. LucAs sHELLFUsE Filed Aug. 24, 1920 Patented May 29, 1923.

UNITED STATS maar OWEN DAvID LUOAS, OE WESTMINSTER, LONDON, ENGLAND, ASSIGNOE To Ivi. L.,

EXPERIMENTAL LIMITED, OE WESTMINSTEE, LONDON,v ENGLAND.

SHELL FUSE.

' Application led August 24, 1920. Serial No. 405,659.

(GRANTED UNDER THE PROVISIONS OF THE ACT- 0F MARCH 3, 1921, 41 STAT, LA., 1313.)

To all whom it may concern:

Be it known that I, OWEN DAVID LUCAS, a subject of the Kin of Great Britain, residing at Vickers IIouse, Broadway, Test minster, in the county of London, England, Ihave invented certain new and useful Improvements in Shell Fuses (for which'IA have filed a patent application in Great Brit# ain on Se teinberl 1st, 1916, and lwhich has issued as atent No. 125,598), of which the *following is a Specification.

This invention relates to shell fuses of the type which has a pistonfacted upon by the pressure of the air dur-ing the flight of the shell,and its obj ect is to provide a fuse which shall be extremely `sensitive and which nevertheless shall be perfectly safe until the shell has travelled some distance from the Gun.

D By my inventioIrI am enabled to Obviate the necessity of employinga spring for the purpose of keeping the striker away from the detonator. n

According to my invention'I form on the front of the striker -a head which offers a small area to the resistance ofthe air, but is preferably designed to cover a large surface of an object against which it Strikes, such as the fabric composing the envelope of an airsliip or the wing of an'aeroplane. This head v v'is carried by aA stem which passes through a hole in the front of the nose of the fusev and carries avpiston which works in a cylinder formed-in 'the fuse and is of an area equal approximately vto the area of the head.

Arrangements are made whereby air can pass from the nose to the cylinder in rear of the pistonso that the pressure behind the piston may be equal to that on the head whatever may be the velocity of the shell in its passage through the air.

In order to counteract anyleakage of air past the stem and past the piston, and in order to lgive a slight resultant pressure tend-` ing ytokeep the striker forward, I provide one or 'more holes'leading from the frontv of the cylinder ,to the Vcurved outer surface of the nose of the shell. These holes vare in-v clined at a suitable angle, say 60, to the. axis of the fuse and terminate in anV annular recess cut around. the nose so that the travel of the shellinducesa slight vacuum infront of the piston.

Preferably a small hole is drilled through the piston so asto give a constantleak and the size of this hole will determine the position of the striker and the strength `of the blow required to move it. against the detonator. i

Preferably also the striker stern is made hollow so as to supply air to the rear of the piston and a hole is formed in the wall of the stem just behind the head so as tov allow of the ready escape of the air in the cylinder when the head is sealed by fabric The striker is normally heldI away from the detonator, that is, in its forward position -by a split collar situated between the head and the nose of the fuse, and round this split collar is wrapped a tape secured by a safety pin supported by a shearing wire and adapti ed to unwrap itself owing to the rotation ofA large effectivev area,.while only presenting a small area'to the action of the air. G G are two halves of a split collar which is seated on `the front ofthe nose of the fuse and supports the head F. One half of the collar has in its inner flat face a recess H' adapted'to receive the end I of a tape shown in Figure 3 andv formed preferably of soft brass, its other end 'J heingturned back to form a loop which may be filled with solder. Then the two halves'of the collar have been placed in position the tape is woundround filling a groove K in the collar and is pre- 'vented from unwinding by a pin L sup-- ported by a shearing wire M ina hole Nin the body A. On firing the pin sets back shearing the wire M and this releases the end' J of the tape, which, owing to the rotation ot' the shell, unwinds itself and. accordingly when the shell has proceeded some distance from the. gunathe' two halves.ofthecollanarely thrown off and the striker is leftabsolutely:l

free. Meanwhile, however, airhas entered the cylinder B through" thev stern E "and-g through a hole'ff) inthe/strikerandtheflatter" I therefore iloats as it were in the fuse.

P are holes passing from the front ofy the cylinder B to a peripheral. grooveQon the curved portion of the fuse. lThe rush of air past, this. Vgroove' causes slightvacuumA in, Jfront of the piston and therefore any air which maylzleakgpastgthe. stenr Ef or' past the f piston C can escape. vR is a small hole drilledy through .the pistonxsot as. to: proyid'e a constantY leak.. S are h'olesf drilled through: thewalh off the stemi jiust behiiirrdthe'heafdf.

lin order that: .theatwoshalveszof the collar.l f maybefiput von ini the correct position z and to\ prevent their rotation, I preferably providerV each; with aipin T projecting; rearwardsroin it and'.A adapted, to beff se ated; .in in' the-:frontfotthe: fuse;V

A groove V is. preferably provided in the` setback' pin. to; allow o-thel escape-of'v the air f behind it.

The strikerfmay beadjlusted tomove back a little=way .when the collarrflies off", andmay' rest with 'its point on'.- the'surfacez of the derv tonator,l arldf it. remains:v iIr this *posi't'i'rmV until. it. encounters some' object,awhenz the striker is atonce: drivenzrearward, theaiirin the'vcyl` inder escapingthrougfhi-th holesfS.

It will be seen that this rearward'movee -Inentlof the striker-dicesI not'depend upon the vstrengtl'r ofthe' blow caused by the-tina.'- terial.' which. the'f'fuse' meets, but.` mayr bel lookedruiponasdue rather. to the. closing by-v suchk material"L of the front :of the" hollowv stem of the striker, owing'to whaich'no more:

air" can pass to'y tliefrea-r ofy the piston;- and to the increase, also= dile to .thel'maiteriah of area o-f-the head-against which area the 'air now presses..l owingy teV which theair Y pressure on. the head-atl `once overcomes' the pressure on the rear of the ipiston;vl

It will be. noticed4 thatthe head F 'isormed integrali withi thestem E, and-thattheI piston Y C is screwed ori-tothe stem.. Vithy this con-u struet1on,: shouldthere be'any set backA on firing, the'. piston C. will strip offy vthe stein,

while-.the striker "isheldfirm, and therefore..4

therecan. be nopremature burst, whereas if.

the. piston vwere.,,madelintegral with the.'

striker. and.thexhead;..were screwed on to it,I

there` would` be .dang-Zerfofv the. striker stripe.'

pingA from ithe...heafl and-prematurely' eX- ploding ytl-iefshellfi f W 4at I claimanddesire secure by Let# .ters- Patentof Athe-nite'dl `States 1,--

1. Inra shell fuse,thecombinationiwiththe striker of headcarriedi 'by saidstrikerand arrangedin front of the. fusa, a V,cylinder groove U Y index', the: area of sarid pistonrbeing; approximatelyfequal to the effective areaot` said head, and means whereby,during:thefliighi? of. theishellf, air. trom'. thel fronti'oilthe' fuse acts` on the 'rearrfa'ce of sasid piston.

the rear 3;. .1in ashell false', thefcombination with the striker' of' a head: carried by saidi striker; fand:

arranged-in: iront 101i the? fuse, a cylind'enrin the fusea'a lpiston:.wihicl'r isvcamied-fby4 y striker:and.A worksv in said cylinder, thm-area# of said piston/beingl Vapproximately equal to theefectiye: areai olf said-xhead,:. andifmeans for conveying air from the front o'rf the-fuse?` tothe s cylinder :in rear, of said pistoni 4'.. Ina shell fuse,.thecombinaftion'with theyv strikerV o a head* carried? 'by said striker. andy arrangedin vfront of-thfusm, a. eylinder'in. thesiuse, aie-piston`r Whichnis carried by saidy striker and-:works in v said, cyln'flerathe area of saidipiston" being approximately equal'jto: the effective area of said head, and a passage-.-

lea-ding; .from then ift-,ont '04% the fuse to the cylinder in'rearot thepiston@` andarranged im front oi-the.fuse,.a.cylinder y 5f. I-n1-a shell fuse,thecombinationwith.`V the striker, of ahead carried bysid-sbriker inthe fuse, apistom whichtis carried by said striker and .works in said` cylindela'the areaV eqiialfgtoof said.; piston being! ,approxi-mately ics.

provided. witha rearward-ly and. .outwardly extendingi'hole lead-ing`v from. the. frontl of the'.

cylinder tov theeiderior of the fuse.

. 6,11 ashellr fuse, the combination Wit-hl the,

striker. cfa headearried by said-strikereand `arraI-iged infront-ofthe fuse, a; cylinder in@ the fuse,-a' pistonlwhieh is. carried-by saidl f ofL said pistour being approximately equal to striker-1 andlworks in saidx cyl-i.nder,.the..area

thev effective area lof said head, means; for.

conveying, air. te.l the vcylinder. inrear .of-said. piston, the. ruse bein-g, providedwith.fa-reary wardly and outwardly extending;y holieleadf-1 ing. from the front .ot the .cylinder lso-fthe' exter'io'rv of the .ii-use..

7. ashel-l fussg. the i they striker; oat ahead emedbysaidstniku;

and arranged' in. front, uitliei'nse' cylinder in the apstomwhchis carried striker. .andiA said, of said-1 piston, being. approximately equnltu i, the l' eiectiye area heaxL. tf hein g. proyi'ded. paa'ge-A the front of the fuse to the cylinder in rear of the piston, the fuse being provided with and arranged in front of the fuse, a cylinder r in the fuse, a piston which is carried by said striker and works in said cylinder, the area of said piston being approximately equal to the effec-tive area of said head, means for conveying air to the cylinder in rear of said piston, the Jfuse being provided with a rearwardly and outwardly extending hole leading from the front of the cylinder to the exterior of the fuse, and means whereby a. constant leak of air is provided from behind said piston during rearward movement of the latter in the cylinder.

9. In a shell fuse,'the combination with the striker of a head carried by said striker and arranged in front of the fuse, a cylinder in the fuse, a piston which is `carried by said striker and works in said cylinder, the area of said piston being approximatelyequal to the effective area of said head, a passage leading from the front of the fuse to the cylinder in rear of said piston, the fuse being provided with a rearwardly and outwardly extending hole leading from the front of the cylinder to the exterior of the fuse and means whereby a constant leak of air is p-rovided from behind said piston during rearward movement of the latter in the cylinder.

10. In a shell fuse, the combination with the striker of a head carried by said striker and arranged in front of the fuse, a cylinder in the fuse, a piston which is carried by said striker and works in said cylinder, the area of said piston being approximately equal to the effective area of said head, the striker being provided with a passage leading 'from the front of the fuse to the cylinder in rear of the piston, said piston `being provided with a hole for providing a constant leak of air from behind said piston during rearward movement of the latter in the cylinder.

11. In a shell fuse, the combination with the striker, of a head carried by said striker and arranged in front of the fuse, a cylinder in the fuse. a. piston which is carried by said striker and works in said cylinder, the area of said piston being approximately equal to the effective area of said head, means for conveying air to thecylinder in rear of said -said collar and a set-back piston, the fuse bein provided with a rear-L i wardly and outward y kextending hole leading from the front of the cylinder totheexterior of the fuse said piston being provided with a hole for providing a constant leak of air from behind said piston during rearward movement ofthe latter in the cylinder.

12. In a shell fuse, the combination with the striker, of a head carried by said striker and arranged in front of the fuse, a cylinder in the fuse, a ypiston which is carried by said striker and works in said cylinder, the area of said piston being approximately equal tothe effective area of said head, and a hollow stem on said striker, said stem conveying air to the cylinder in rear of said piston and being formed with a hole just behind the head. f Y

13. In a shell fuse, the combinationwith the striker of a head carried by. said striker n and arranged in front of the fuse, av

cylinder in the fuse, a piston which is carried by said striker and works in said cylinder, the area of saidpiston'being approximately equal to the effective area of said head, a split collar `for holding the c striker in the safe position, a tape wrapped round said collar and a'set-backpin for liolding said tape in position. Y V

14. In a shell fuse, the combination with the striker of a headcarried by said striker and arranged in front of the fuse, a cylinder in the fuse, a piston which is carried by said striker and works in said cylinder, the area kof ysaid piston being approximately equal to the effective area of said head, means for yconvey-ing air to the cylinder in rear of said piston, a split collar for holding the striker in the safe position, a tape wrapped round pin for holding said tape in position. I y

15. In a shell fuse, the combination with the striker of a head carried by said striker and arranged in front of the fuse, a cylinder in the fuse, a piston which is carried by said striker and works in'said cylinder, the area of said pistonbeing approximately equal to the effective area of said head, a passage `leading from the front of the fuse to the cylinder in rear of the piston, lsplit collar for holding the striker in the safe position, a tape f wrapped round said collar and a set-back pin for holding said tape in position. f

In testnnony whereof I affixv my signature.l i

o'wEN DAVID LUcA's. 

